This invention relates generally to a watch crystal. In particular, the present invention relates to an adjustable watch crystal apparatus.
Most people become farsighted with age, making it difficult for them to read an ordinary wristwatch without glasses. Today, most watches designed for visually impaired people are made with large faces and large numbering. Although effective, these watches are rarely attractive. Because wristwatches are often employed equally for function and style, unattractiveness is a significant shortcoming. A watch crystal that corrects farsightedness without an abnormally large face would overcome these issues and be greatly appreciated.
At the same time, however, it is important for people with varying degrees of farsightedness to be able to use the same watch. Otherwise, a customer would essentially have to get a prescription for his watch, which would provide only limited appeal.
Various proposals for magnifying watch crystals are found in the art. U.S. Pat. No. 5,566,137 discloses a fixed mirror and enlarging lens arrangement in which light is reflected internally and then bent before passing through the watch crystal. U.S. Pat. Nos. 5,883,860 and 6,275,333 disclose magnifying devices that are removably or pivotally attached to the outside of the watch crystal for magnifying the watch face. U.S. Pat. No. 6,406,769 discloses a watch crystal with a non-adjustable recess machined in the crystal's lower face for magnifying the watch face.
While assumably effective for their intended purposes, the existing devices do not provide a watch crystal that corrects varying degrees of farsightedness, adjusts easily, is stylish and attractive, is lightweight, utilizes optically clear polymers, and that can be incorporated into virtually any style of wristwatch. Therefore, it would be desirable to have a watch crystal having these features.